Can't seem to find a big enough fuse block

[viper1216]

Just picked up a new to me boat. 2001 Maxum 2400scr. Was advised that there were some electrical issues. Looking at the fuse block and it seems to be kinda toast. One fuse slot is literally melted. So figured I would just replace the whole block than try to chase down electrical demons. In looking at it, there are 18 total fuses. 9 down each side. But I can't seem to find an 18 circuit panel anywhere. The biggest seems to be 12. Is there an 18 somewhere, or do I have to get a 12 circuit and then a 6? The ones I have been looking at are Blue Sea 12 circuit with Negative Bus. My only question is can I just jump power and ground from the 12 to the 6? Basically the main 12v input and ground to the 12 circuit one. And then a short jumper cable to the for pos and neg to the 6 slot input? I don't want to have to run a whole other 12v and neg cable to the back of the boat if I can avoid it.
Thanks!!

 

[alldodge]

18 circuits for a 24 footer is a bunch. Could use an automotive block but would need to bypass the 4-way and turn single flasher

Could use individual breakers and make your own panel

 

[dingbat]

No problem daisy chaining the two blocks together if the wiring is sized correctly.

 

[viper1216]

Thanks. Only reason I was going 18 circuits is to match what's there. Figured could just to a 1:1 swap for all of them. Nothing is labeled, so I have no idea what fuse goes to what.

 

[matt167]

I really, really like the Blue Sea Systems fuse blocks. High quality and fairly inexpensive although they have gone up since I last bought one.

You'll have no problem using a ~10-12ga wire to daisy chain 2 of them. Put your lighter loads on the second one

 

[dingbat]

Not properly sizing the wiring is what gets people into trouble in this excerise.

The 18 circuit block is rated to 100 amps.
The 6 circuit is 100 amp as well

1. Wiring to fuse blocks should have no more than a 3% drop.
2. Length of wire from source to fuse block and back to source = X

Not knowing the length of run you need to accommodate, I’ll substitute the circuit length on my boat (22’ boat) which was roughly 25 feet.

200 amp @ 25’ @ 3% = 3/0 AWG wire for both positive and ground wires

A little crazy huh....

So let’s add up the values on the existing fuse block and solve
135 amp @ 25’ @ 3%= 2/0 AWG feed

Still crazy.....Seriously doubt all those circuits are fused correctly

In reality, you really need to figure out the current draw of each circuit to calculate the total load on the fuse block.
Good time to educate yourself on what circuit supplies what. Mark and fuse everything accordingly.

 

[viper1216]

I'm pretty sure that is the stock fuse block. I had a 2004 Maxum prior to this and it looks just like that same panel. That one was smaller since it was a smaller boat and didn't have as many bells and whistles, but same style. I found a wiring diagram for it it it looks like it does in fact have 18 circuits. I'm going to use the existing power supply straight to the 12 circuit. It looks to be 12 AWG wire I think. Figured I would use 10 for the chain wire. It's only going to be a few inches long so hopefully no issue there. I ordered the 12 and 6 circuit blocks, so I'll start playing with this in a few days when they come in.

 

[viper1216]

Follow up question...I have a shore power panel as well inside the cabin area for things like fridge, hot water heater, range and 120 receptacles. Do those items ONLY work when I am connected to shore power? So if I take the boat out the for the day, the fridge isn't going to be working?

 

[matt167]

For those things to work on the water, you need an inverter or a generator

 

[alldodge]

See if you have a breaker or fuse on the 12V side for the fridge. If one is there then it will switch to 12V when shore power is removed. If nothing on the 12V side, no go

 

[matt167]

BUT, like your house, if you loose power, your fridge will still be cold enough for a day or better.

 

[viper1216]

So I had to pull the fridge out to get to some thru hull fittings that broke. Gave me a good look of the back of it. The fridge is wired for 12v and then plugs into a 120 receptacle as well. So I'm guessing it runs off both and switches dependent on power source. Will have to figure out if there is some sort of switch for it somewhere, as it is not currently running and the battery is connected and powered up. Maybe it only runs with key on.

 

[alldodge]

Normally the 12V/120AC will automatically switch over to 12V when shore power is disconnected. That said there is usually a breaker on the 12V side, or could be a fuse and a switch. Might be the 12V line is not connected

What size house bat does it have?

 

[viper1216]

So in reading, apparently there is a switch inside the fridge. Should prob check that lol. My wife was the one who cleaned it out, I haven't even opened it yet. I'll have to take a look at it once I put it back in. I of course got the wrong size thru hull fitting (3rd times the charm). Once those are replaced I'll pop it back in and figure it out from there. Could be a fuse block issue as well. I was having issues with the interior lights not working. Chased down the circuit and if wiggle the spade connection at the fuse block they worked. So I'm going to hold off on messing with anything electrical until I replace those. Then at least I know I have a good power source. Alldodge...not sure on the battery sizes. They are covered and I haven't looked at em yet, but there are 2 of them.